A Simulation Study to Assess the Effect of the Number of Response Categories on the Power of Ordinal Logistic Regression for Differential Item Functioning Analysis in Rating Scales

Table 4

The power of OLR model under different combinations when .

Conditions	Ratio	DIF = 0.5			DIF = 1
		1		0.97	0.97	0.99	1.00	1.00	1.00
	0.94		0.95	0.96	1.00	1.00	1.00
	0.88		0.89	0.93	1.00	1.00	1.00
2		0.95	0.96	0.98	1.00	1.00	1.00
		0.93	0.93	0.94	1.00	1.00	1.00
		0.89	0.89	0.90	1.00	1.00	1.00
3		0.73	0.73	0.77	0.99	1.00	1.00
		0.72	0.71	0.76	1.00	1.00	1.00
		0.62	0.61	0.66	1.00	1.00	1.00
4		0.98	0.98	0.99	1.00	1.00	1.00
		0.97	0.98	0.97	1.00	1.00	1.00
		0.94	0.95	0.95	1.00	1.00	1.00
5		0.95	0.96	0.97	1.00	1.00	1.00
		0.92	0.92	0.94	1.00	1.00	1.00
		0.84	0.87	0.89	1.00	1.00	1.00
6		0.98	0.98	0.98	1.00	1.00	1.00
		0.97	0.98	0.98	1.00	1.00	1.00
		0.94	0.96	0.96	1.00	1.00	1.00
7		0.94	0.94	0.95	1.00	1.00	1.00
		0.92	0.88	0.92	1.00	1.00	1.00
		0.85	0.85	0.88	1.00	1.00	1.00
8		0.91	0.91	0.94	1.00	1.00	1.00
		0.86	0.88	0.92	1.00	1.00	1.00
		0.79	0.81	0.85	1.00	1.00	1.00
9		0.55	0.54	0.61	0.99	1.00	1.00
		0.45	0.45	0.53	0.99	0.99	1.00
		0.39	0.40	0.44	0.98	0.98	0.99

: number of response categories.
: and , : and , : and .
The conditions are described in Table 1.